KAUSHAL, RAJESHTHAKUR, SANGEETA2017-01-192017-01-19200947086http://krishikosh.egranth.ac.in/handle/1/97045ABSTRACT The present investigations entitled “Evaluation of carriers and methods of application for plant growth promoting rhizobacterial (PGPR) inoculants on apple” was carried out during 2007-2009. An attempt was made to evaluate different carrier materials,viz. charcoal,peat,talc powder, vermicompost and vermiculite and to standardize the methods of application of carrier based / liquid formulation of Bacillus megaterium on apple under net house conditions .The relationship of optical density with viable cell counts and quantity of inoculum with carrier material was established. The viable counts decrease with increase in storage period irrespective of carrier materials. Charcoal was found to be best carrier material to retain maximum number of viable cells after 180 days of storage. The effect of liquid shake culture prepared in nutrient broth was more effective compared to water based rest culture. The inoculation of carrier based formulation excels to register their effects on seed germination and other plant growth parameters over liquid (rest /shake) formulation. The application of charcoal based inoculum in sterilized vermicompost has not only significantly influenced seed germination, shoot length, root length, leaf size and number of leaves, but also improved the available nitrogen and phosphorus content of the soil. These findings clearly reveal that charcoal is the best carrier material to retain long shelf life of Bacillus megaterium and the application of charcoal based inoculum with sterilized vermicompost is the best method to produce healthy seedlings of apple.enThesis